Other operating expenses, net (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other Income and Expenses [Abstract]
Acquisition and integration related expenses	$ 17.5	$ 77.1
Stock-based compensation expense	5.7	6.0
Restructuring charges	2.5	0.1
Other employee severance costs	5.5	12.9
Other facility closure costs	1.9	0.0
Saccharin legal settlement	0.0	62.5
Fair value adjustment for warrants	(26.3)	(4.4)
(Gain) loss on sale of property, plant and equipment	(5.3)	0.1
Other	2.6	10.5
Total other operating expenses, net	$ 4.1	$ 164.8